Share this with others: Alcohol, which is consumed in beverages such as liquor, wine and beer, is a chemical called ethanol. Ethanol may cause headaches by several means. First, it is a direct vasodilator; in some individuals vasodilation may cause a headache.
In medicine, a contraindication is a condition or factor that serves as a reason to withhold a certain medical treatment due to the harm that it would cause the patient. Contraindication is the opposite of indication, which is a reason to use a certain treatment. Some contraindications are absolute, meaning that there are no reasonable circumstances for undertaking a course of action.
Contraindications include current, past or suspected breast cancer, known or suspected estrogen-dependent malignant tumours, previous idiopathic or current venous thromboembolism, known coronary heart disease, and porphyria cutanea tarda (absolute contraindication).